EVIDENCE FOR A MULTICOMPONENT SEX-PHEROMONE IN ERIBORUS-TEREBRANS (GRAVENHORST) (HYM, ICHNEUMONIDAE), A LARVAL PARASITOID OF THE EUROPEAN CORN-BORER

Sex Pheromone activity of Eriborus terebrans (Gravenhorst) (Hymonoptera: Ichneumonidae) was recovered from acetone rinses of flasks that previously contained females. The acetone flask rinses elicited the following male responses: upwind anemotaxis, casting, hovering, landing, wing-fanning, and mating attempts with other nearby males. Activity of the acetone flask rinse lasted up to four days on a glass substrate. Polar component and nonpolar components were demonstrated in the acetone flask rinse. The polar component elicited male behavioral responses similar to those by the acetone flask rinse, although retention of males at the pheromone source and the period of wing-fanning were of shorter duration. Chromatography data and chemical derivatization indicated that the polar component had the properties of a carboxylic acid with an additional oxygen-containing functional group. The nonpolar component acted as a synergist since it was inactive alone but increased male behavioral responses when added to the polar component. Florisil open column chromatography suggested that the nonpolar component was a hydrocarbon(s).